futility: updater: Preserve SMMSTORE and add quirk 'eve_smm_store'

The 'SMM store' must be preserved during firmware update. On newer systems,
this can be done by preserving FMAP section 'SMMSTORE' (CL:1221210).

For Eve, the SMM store did not have its own FMAP section and needs to be
reserved by explicit cbfstool calls.

BRANCH=None
BUG=b:70682365
TEST=make futil; tests/futility/run_test_scripts.sh $(pwd)/build/futility

Change-Id: Ica043f51de0170b5c40f61d059437b9572025e2e
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1250464
Reviewed-by: Joel Kitching <kitching@chromium.org>

4 files changed, 107 insertions, 0 deletions

diff --git a/futility/updater.c b/futility/updater.c
index d5bc88e2..5480f7e9 100644
--- a/futility/updater.c
+++ b/futility/updater.c
@@ -955,6 +955,7 @@ static int preserve_images(struct updater_config *cfg)
 		FMAP_RW_PRESERVE,
 		FMAP_RW_NVRAM,
 		FMAP_RW_ELOG,
+		FMAP_RW_SMMSTORE,
 		/*
 		 * TODO(hungte): b/116326638: Remove RO_FSG after the migration
 		 * is finished.
@@ -1539,6 +1540,9 @@ enum updater_error_codes update_firmware(struct updater_config *cfg)
 	if (try_apply_quirk(QUIRK_ENLARGE_IMAGE, cfg))
 		return UPDATE_ERR_SYSTEM_IMAGE;
 
+	if (try_apply_quirk(QUIRK_EVE_SMM_STORE, cfg))
+		return UPDATE_ERR_INVALID_IMAGE;
+
 	if (debugging_enabled)
 		print_system_properties(cfg);
 
diff --git a/futility/updater.h b/futility/updater.h
index 3134bbbc..58445a1c 100644
--- a/futility/updater.h
+++ b/futility/updater.h
@@ -32,6 +32,7 @@ static const char * const FMAP_RO_FRID = "RO_FRID",
 		  * const FMAP_RW_ELOG = "RW_ELOG",
 		  * const FMAP_RW_PRESERVE = "RW_PRESERVE",
 		  * const FMAP_RW_LEGACY = "RW_LEGACY",
+		  * const FMAP_RW_SMMSTORE = "SMMSTORE",
 		  * const FMAP_SI_DESC = "SI_DESC",
 		  * const FMAP_SI_ME = "SI_ME";
 
@@ -78,6 +79,7 @@ enum quirk_types {
 	QUIRK_MIN_PLATFORM_VERSION,
 	QUIRK_UNLOCK_ME_FOR_UPDATE,
 	QUIRK_DAISY_SNOW_DUAL_MODEL,
+	QUIRK_EVE_SMM_STORE,
 	QUIRK_MAX,
 };
 
diff --git a/futility/updater_quirks.c b/futility/updater_quirks.c
index 6a3fa222..c1d937af 100644
--- a/futility/updater_quirks.c
+++ b/futility/updater_quirks.c
@@ -9,6 +9,8 @@
 #include <assert.h>
 #include <stdio.h>
 #include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
 
 #include "updater.h"
 #include "host_misc.h"
@@ -31,6 +33,9 @@ static const struct quirks_record quirks_records[] = {
 	{ .match = "Google_Caroline.", .quirks = "unlock_me_for_update" },
 	{ .match = "Google_Cave.", .quirks = "unlock_me_for_update" },
 
+	{ .match = "Google_Eve.",
+	  .quirks = "unlock_me_for_update,eve_smm_store" },
+
 	{ .match = "Google_Poppy.", .quirks = "min_platform_version=6" },
 	{ .match = "Google_Scarlet.", .quirks = "min_platform_version=1" },
 
@@ -220,6 +225,81 @@ static int quirk_daisy_snow_dual_model(struct updater_config *cfg)
 }
 
 /*
+ * Extracts files from a CBFS on given region (section) of image_file.
+ * Returns the path to a temporary file on success, otherwise NULL.
+ */
+static const char *extract_cbfs_file(struct updater_config *cfg,
+				     const char *image_file,
+				     const char *cbfs_region,
+				     const char *cbfs_name)
+{
+	const char *output = create_temp_file(cfg);
+	char *command, *result;
+
+	if (asprintf(&command, "cbfstool \"%s\" extract -r %s -n \"%s\" "
+		     "-f \"%s\" 2>&1", image_file, cbfs_region,
+		     cbfs_name, output) < 0) {
+		ERROR("Failed to allocate internal buffer.");
+		return NULL;
+	}
+	result = host_shell(command);
+	free(command);
+
+	if (!*result)
+		output = NULL;
+
+	free(result);
+	return output;
+}
+
+/*
+ * Quirk to help preserving SMM store on devices without a dedicated "SMMSTORE"
+ * FMAP section. These devices will store "smm store" file in same CBFS where
+ * the legacy boot loader lives (i.e, FMAP RW_LEGACY).
+ * Note this currently has dependency on external program "cbstool".
+ * Returns 0 if the SMM store is properly preserved, or if the system is not
+ * available to do that (problem in cbfstool, or no "smm store" in current
+ * system firmware). Otherwise non-zero as failure.
+ */
+static int quirk_eve_smm_store(struct updater_config *cfg)
+{
+	const char *smm_store_name = "smm store";
+	const char *temp_image = create_temp_file(cfg);
+	const char *old_store;
+	char *command;
+
+	if (write_image(temp_image, &cfg->image_current) != VBERROR_SUCCESS)
+		return -1;
+
+	old_store = extract_cbfs_file(cfg, temp_image, FMAP_RW_LEGACY,
+				      smm_store_name);
+	if (!old_store) {
+		DEBUG("cbfstool failure or SMM store not available. "
+		      "Don't preserve.");
+		return 0;
+	}
+
+	/* Reuse temp_image. */
+	if (write_image(temp_image, &cfg->image) != VBERROR_SUCCESS)
+		return -1;
+
+	/* crosreview.com/1165109: The offset is fixed at 0x1bf000. */
+	if (asprintf(&command,
+		     "cbfstool \"%s\" remove -r %s -n \"%s\" 2>/dev/null; "
+		     "cbfstool \"%s\" add -r %s -n \"%s\" -f \"%s\" "
+		     " -t raw -b 0x1bf000", temp_image, FMAP_RW_LEGACY,
+		     smm_store_name, temp_image, FMAP_RW_LEGACY,
+		     smm_store_name, old_store) < 0) {
+		ERROR("Failed to allocate internal buffer.");
+		return -1;
+	}
+	host_shell(command);
+	free(command);
+
+	return reload_image(temp_image, &cfg->image);
+}
+
+/*
  * Registers known quirks to a updater_config object.
  */
 void updater_register_quirks(struct updater_config *cfg)
@@ -248,6 +328,12 @@ void updater_register_quirks(struct updater_config *cfg)
 	quirks->name = "daisy_snow_dual_model";
 	quirks->help = "b/35525858; needs an image RW A=[model x16], B=x8.";
 	quirks->apply = quirk_daisy_snow_dual_model;
+
+	quirks = &cfg->quirks[QUIRK_EVE_SMM_STORE];
+	quirks->name = "eve_smm_store";
+	quirks->help = "b/70682365; preserve UEFI SMM store without "
+		       "dedicated FMAP section.";
+	quirks->apply = quirk_eve_smm_store;
 }
 
 /*
diff --git a/tests/futility/test_update.sh b/tests/futility/test_update.sh
index 1b80e2e5..d45e114c 100755
--- a/tests/futility/test_update.sh
+++ b/tests/futility/test_update.sh
@@ -287,3 +287,18 @@ if type flashrom >/dev/null 2>&1; then
 		-i "${TO_IMAGE}" --wp=0 --sys_props 0,0x10001,1,3 >&2
 	cmp "${TMP}.emu" "${TMP}.expected.full"
 fi
+
+if type cbfstool >/dev/null 2>&1; then
+	echo "SMM STORE" >"${TMP}.smm"
+	truncate -s 262144 "${TMP}.smm"
+	cp -f "${FROM_IMAGE}" "${TMP}.from.smm"
+	cp -f "${TMP}.expected.full" "${TMP}.expected.full_smm"
+	cbfstool "${TMP}.from.smm" add -r RW_LEGACY -n "smm store" \
+		-f "${TMP}.smm" -t raw
+	cbfstool "${TMP}.expected.full_smm" add -r RW_LEGACY -n "smm store" \
+		-f "${TMP}.smm" -t raw -b 0x1bf000
+	test_update "Legacy update (--quirks eve_smm_store)" \
+		"${TMP}.from.smm" "${TMP}.expected.full_smm" \
+		-i "${TO_IMAGE}" --wp=0 --sys_props 0,0x10001,1 \
+		--quirks eve_smm_store
+fi